Autostereoscopic display device

ABSTRACT

The present invention provides an autostereoscopic display device including: a display device; and a liquid crystal lens cell arranged on the display device, the liquid crystal lens cell including: a first substrate; a second substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate; a first electrode arranged on the first substrate on the side of the liquid crystal layer; and a second electrode arranged on the second substrate on the side of the liquid crystal layer, in which the liquid crystal lens cell has a water-absorption layer arranged on at least one of the first substrate and the second substrate on the side of the liquid crystal layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 13/740,384, filed on Jan. 14, 2013. Further, thisapplication claims priority from Japanese Patent ApplicationJP2012-009591 filed on Jan. 20, 2011, the entire contents of which arehereby incorporated by reference into this Application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a stereoscopic display device (3-Ddisplay device), and particularly to a useful technique by being appliedto a lenticular-type stereoscopic display device using liquid crystallens cells.

2. Description of the Related Art

As a stereoscopic display device (3-D display device) with whichstereoscopic images (3-D images) can be viewed without dedicatedeyeglasses, a device using a lenticular lens has been known.

In the stereoscopic display device using the lenticular lens, forexample, the lenticular lens is arranged on a display surface such as aliquid crystal display panel, images for the left and right eyes arealternately displayed on the liquid crystal display panel, and theimages for the left and right eyes are separated from each other by thelenticular lens. An observer observes the images for the left and righteyes separated through the lenticular lens with his/her left and righteyes, respectively, so that a three-dimensional stereoscopic image canbe observed.

Japanese Patent Application Laid-Open No. Hei 7-217374 discloses astereoscopic display device using a lenticular lens in which a liquidcrystal lens cell is used as the lenticular lens.

The liquid crystal lens cell has therein only a transparent conductivefilm (for example, ITO (Indium Tin Oxide)) configuring an electrode,bead spacers to keep the intervals of cells constant, and an oriented orinorganic insulating film, and has the small number of members to absorbwater.

Therefore, if the stereoscopic display device using the liquid crystallens cell is in a high temperature and humidity environment, moistureenters a liquid crystal layer of the liquid crystal lens cell, and themoisture dissolved in the liquid crystal layer is disadvantageouslyeluted if the temperature is lowered.

The present invention has been achieved to solve the above-describedproblems of the conventional technique, and an object of the presentinvention is to provide a technique capable of preventing moisturedissolved in a liquid crystal layer of a liquid crystal lens cell frombeing eluted when the temperature is lowered in a stereoscopic displaydevice using the liquid crystal lens cell.

The above and other objects, and novel characteristics of the presentinvention will become apparent from the description of the specificationand the accompanying drawings.

SUMMARY OF THE INVENTION

The followings are summaries of representative aspects of the inventiondisclosed in the application.

(1) The present invention provides a stereoscopic display deviceincluding: a display device; and a liquid crystal lens cell arranged onthe display device, the liquid crystal lens cell including: a firstsubstrate; a second substrate; a liquid crystal layer sandwiched betweenthe first substrate and the second substrate; a first electrode arrangedon the first substrate on the side of the liquid crystal layer; and asecond electrode arranged on the second substrate on the side of theliquid crystal layer, wherein the liquid crystal lens cell has awater-absorption film arranged on at least one of the first substrateand the second substrate on the side of the liquid crystal layer.(2) In (1), the water-absorption film is made of acrylic resin or epoxyresin.(3) In (1), the water-absorption film is arranged between the firstsubstrate and the first electrode, or on the first electrode on the sideof the liquid crystal layer.(4) In (1), the water-absorption film is arranged between the secondsubstrate and the second electrode, or on the second electrode on theside of the liquid crystal layer.(5) In (1), 7.5<(d/Th)<100 is satisfied, where the thickness of theliquid crystal layer is d and the thickness of the water-absorption filmis Th.(6) In (1), the first electrode is a comb-like electrode, the secondelectrode is a plane-like electrode, and 3.5<(Q/d)<7, preferably4.5<(Q/d)<5.5, or more preferably (Q/d)=5 is satisfied, where thethickness of the liquid crystal layer is d and the pitch of thecomb-like electrode is Q.(7) In (1), the first electrode is a comb-like electrode, the secondelectrode is a plane-like electrode, and 10<(Q/L), or preferably15<(Q/d)<20 is satisfied, where the pitch of the comb-like electrode isQ and the width of the comb-like electrode is L.(8) In (1), bead spacers arranged inside the liquid crystal layer areprovided, and the number of bead spacers per 1 mm² of the liquid crystallayer is 10 or less.

The following is a summary of an effect obtained by representativeaspects of the invention disclosed in the application.

According to the present invention, it is possible to prevent moisturedissolved in a liquid crystal layer of a liquid crystal lens cell frombeing eluted when the temperature is lowered in a stereoscopic displaydevice using the liquid crystal lens cell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram for showing an outline configuration of astereoscopic display device according to a first embodiment of thepresent invention;

FIG. 2 is a cross-sectional view for showing a cross-sectional structureof a liquid crystal lens cell shown in FIG. 1;

FIGS. 3A and 3B are diagrams for showing the electrode shapes of a firstelectrode and a second electrode shown in FIG. 2;

FIGS. 4A, 4B, and 4C are diagrams each explaining an operation of theliquid crystal lens cell shown in FIG. 2;

FIG. 5 is a graph for showing a result of having simulated an impact oncrosstalk by a ratio (Q/d) of the pitch Q of a comb-like electrodeconfiguring the first electrode to the thickness d of a liquid crystallayer;

FIG. 6 is a graph for showing a result of having simulated an impact oncrosstalk by a ratio (Q/L) of the pitch Q of the comb-like electrodeconfiguring the first electrode to the width L of the comb-likeelectrode when (Q/d) is 5;

FIG. 7A is an outline view for showing a state of bead spacers dispersedin the liquid crystal lens cell according to the first embodiment of thepresent invention;

FIG. 7B is an outline view for showing a state of bead spacers dispersedin a general liquid crystal display panel (a TN-type or STN-type liquidcrystal display panel);

FIG. 8 is a graph for showing a relation between a water vapor pressureand the amount of moisture entering the liquid crystal layer;

FIG. 9 is a graph for showing a result obtained by measuring a timerequired until moisture that enters when the liquid crystal lens cell isleft in a high temperature and humidity environment (left for 500 hr inan environment such as a temperature of 70° C. and a humidity of 90%) isabsorbed by a water-absorption film, while the thickness of thewater-absorption film arranged in the liquid crystal lens cell ischanged;

FIG. 10 is a cross-sectional view for showing a cross-sectionalstructure of a liquid crystal lens cell of a stereoscopic display deviceaccording to a second embodiment of the present invention; and

FIG. 11 is a cross-sectional view for showing a cross-sectionalstructure of a liquid crystal lens cell of a stereoscopic display deviceaccording to a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

Hereinafter, modes for carrying out the present invention will bedescribed using the drawings based on embodiments. Each of the followingembodiments shows a concrete example of content of the presentinvention. The present invention is not limited to the embodiments, butcan be variously changed and modified by those skilled in the art withina range of technical ideas disclosed in the specification.

Further, the following embodiments are not meant to limit theinterpretation of the claims of the present invention.

Furthermore, the constitutional elements having the same functions aregiven the same reference numerals throughout the all drawings forexplaining the embodiments, and the explanations thereof will not berepeated in some cases.

First Embodiment

FIG. 1 is a block diagram for showing an outline configuration of astereoscopic display device according to a first embodiment of thepresent invention.

As shown in FIG. 1, the stereoscopic display device of the embodimentincludes a display device 100 and a liquid crystal lens cell 101. Forthe display device 100, used is a liquid crystal display panel or anorganic EL display panel that is a self-luminous display.

The liquid crystal lens cell 101 is attached on the display device 100through a transparent adhesive member 102. In this case, for example, UVcured resin or the like is used for the transparent adhesive member 102.

FIG. 2 is a cross-sectional view for showing a cross-sectional structureof the liquid crystal lens cell 101 shown in FIG. 1.

As shown in FIG. 2, the liquid crystal lens cell 101 includes a firstsubstrate (SUB1), a second substrate (SUB2), and a liquid crystal layer(LC) sandwiched between the first substrate (SUB1) and the secondsubstrate (SUB2). The first substrate (SUB1) and the second substrate(SUB2) are configured using, for example, transparent substrates such asglass substrates. In this case, the surface of the first substrate(SUB1) on the side opposed to the liquid crystal layer (LC) is attachedon the display device 100 through the adhesive member 102. Thus, thesurface of the second substrate (SUB2) on the side opposed to the liquidcrystal layer (LC) serves as an observing surface observed by anobserver.

On the surface of the first substrate (SUB1) on the side of the liquidcrystal layer (LC), a first electrode (EL1) is formed on which anoriented film (AL1) is formed. Likewise, on the surface of the secondsubstrate (SUB2) on the side of the liquid crystal layer (LC), a secondelectrode (EL2) is formed on which an oriented film (AL2) is formed. Itshould be noted that bead spacers used to keep the interval of theliquid crystal layer (LC) constant are not illustrated in FIG. 2.

In FIG. 2, the reference numeral 10 denotes a water-absorption film. Thewater-absorption film 10 is desirably a film made of water-absorbing,transparent organic material, and for example, transparent acrylic resinor epoxy resin is used. Acrylic resin is especially desirable due to itsexcellent water absorbability.

In this case, the oriented films (AL1 and AL2) are horizontallyoriented. Further, positive dielectric constant anisotropy material isused for the liquid crystal layer (LC).

FIGS. 3A and 3B are diagrams for showing the electrode shapes of thefirst electrode (EL1) and the second electrode (EL2) shown in FIG. 2.The second electrode (EL2) is a plane-like electrode as shown in FIG.3A, and the first electrode (EL1) is a comb-like electrode as shown inFIG. 3B.

In this case, the first electrode (EL1) and the second electrode (EL2)are configured using, for example, transparent electrodes made of ITO(Indium Tin Oxide). It should be noted that FIG. 2 illustrates across-sectional structure taken along the section line A-A′ of FIG. 3B.

FIGS. 4A, 4B, and 4C are diagrams each explaining an operation of theliquid crystal lens cell 101 shown in FIG. 2. It should be noted inFIGS. 4A, 4B, and 4C that the reference numeral 20 denotes lines ofelectric force and 30 denotes liquid crystal molecules.

Alternating-current voltage is applied between the first electrode (EL1)and the second electrode (EL2). For example, if high-potential voltagehigher than that for the second electrode (EL2) is applied to the firstelectrode (EL1), the lines of electric force 20 are generated in thedirection from the first electrode (EL1) towards the second electrode(EL2) as shown in FIG. 4A. Although not shown in the drawing, ifhigh-potential voltage higher than that for the first electrode (EL1) isapplied to the second electrode (EL2), the lines of electric force 20are generated in the direction from the second electrode (EL2) towardsthe first electrode (EL1).

Further, in a state where no voltage is applied between the firstelectrode (EL1) and the second electrode (EL2), the liquid crystalmolecules 30 are in parallel with the first substrate (SUB1) and thesecond substrate (SUB2) as shown in FIG. 4B. In this case, an imagedisplayed on the display device 100 passes through as it is, and thus anobserver can observe a two-dimensional image.

In addition, in a state where voltage is applied between the firstelectrode (EL1) and the second electrode (EL2), the liquid crystalmolecules 30 are aligned in the electric field direction as shown inFIG. 4C and the refractive index distribution of the liquid crystallayer (LC) is changed. Thus, when images for the left and right eyesthat are alternately displayed on the display device 100 pass throughthe liquid crystal lens cell 101, the travelling directions thereof arechanged and the images are separated from each other. Accordingly, anobserver observes the images for the left and right eyes separatedthrough the liquid crystal lens cell 101 with his/her left and righteyes, respectively, so that a three-dimensional stereoscopic image canbe observed. It should be noted that the principle in which athree-dimensional stereoscopic image develops in the stereoscopicdisplay device of the embodiment is described in Japanese PatentApplication Laid-Open No. Hei 7-217374.

As described above, a two-dimensional image and a three-dimensionalimage can be switched to each other using a lens effect (GRIN lens) bythe refractive index distribution of the liquid crystal lens cell 101 inthe embodiment.

In FIG. 2, d represents the thickness of the liquid crystal layer (LC),Q represents the pitch of the comb-like electrode configuring the firstelectrode (EL1), and L represents the width of the comb-like electrode.Accordingly, S=Q-L is satisfied.

FIG. 5 is a graph for showing a result of having simulated an impact oncrosstalk by a ratio (Q/d) of the pitch Q of the comb-like electrodeconfiguring the first electrode (EL1) to the thickness d of the liquidcrystal layer (LC).

It should be noted that the crosstalk represents a fraction of imagesfor the right eye mixed in images for the left eye (or a fraction ofimages for the left eye mixed in images for the right eye) in a statewhere voltage is applied between the first electrode (EL1) and thesecond electrode (EL2) to display a three-dimensional stereoscopicimage.

People hardly recognize 1% or less of crosstalk with their eyes. Thus,as being apparent from FIG. 5, (Q/d) is desirably 3.5<(Q/d)<7. Morepreferably, (Q/d) is 4.5<(Q/d)<5.5 in order to decrease the crosstalk.Further, much more preferably, (Q/d) is about 5 (Q/d≈5). Specifically,when (Q/d) is 5, it is possible to obtain the best lens effect.

FIG. 6 is a graph for showing a result of having simulated an impact oncrosstalk by a ratio (Q/L) of the pitch Q of the comb-like electrodeconfiguring the first electrode (EL1) to the width L of the comb-likeelectrode when (Q/d) is 5.

As being apparent from FIG. 6, Q/L is desirably 15<(Q/L)<20. Further,Q/L is more desirably 10<(Q/L) when the crosstalk is 1% or less.

FIG. 7A is an outline view for showing a state of bead spacers (BS)dispersed in the liquid crystal lens cell 101 of the embodiment. Itshould be noted that FIG. 7B shows a state of bead spacers (BS)dispersed in a general liquid crystal display panel (a TN-type orSTN-type liquid crystal display panel) as a comparison example.

In order to obtain the lens effect, the liquid crystal lens cell 101needs to have a large retardation (Δn×d). In the embodiment, thethickness (d) of the liquid crystal layer (LC) is set at, for example,30 μm. In this case, the bead spacers (BS) each having a size of atleast 20 μm or larger are necessary.

Therefore, the bead spacers (BS) become visible by an observer. Thus, asshown in FIG. 7A, the number of bead spacers is desirably 1 per 1 mm²(1/mm²) in the case of the liquid crystal lens cell 101. In addition, itis necessary to disperse the bead spacers at a density of 10 per 1 mm²(10/mm²) or less at the most.

On the other hand, as shown in FIG. 7B, it is common to disperse thebead spacers at a density of 100 to 200 per 1 mm² (100 to 200/mm²) inthe general liquid crystal display panel.

The circumference of the liquid crystal display panel used in theembodiment is sealed with a seal member (not shown). However, if theliquid crystal display panel is left in a high temperature and humidityenvironment (for example, temperature: 70° C., humidity: 90%, watervapor pressure: about 281 hPa), moisture enters the inside of the liquidcrystal layer (LC) at 0.06 ppm/hr. If the seal member is changed, thisvelocity is accordingly changed. However, the velocity is not largelychanged. The moisture enters mainly from the seal member and a substrateinterface. Thus, if the gap is changed, the velocity is not largelychanged.

The moisture that has entered is absorbed by the liquid crystal layer(LC), the bead spacers (BS), and the oriented films (AL1 and AL2). Inthis case, the velocity of the amount of moisture absorbed by the beadspacers (BS) is dependent on the surface area of the bead spacers (BS).

The surface area of the bead spacer (BS) having a diameter of 30 μm usedin the liquid crystal lens cell 101 is about 2827 μm², whereas thesurface area of the bead spacer (BS) having a diameter of 4 μm used inthe general liquid crystal display panel is about 50 μm².

In this case, it is assumed that 10 bead spacers (BS) per 1 mm² areprovided in the liquid crystal lens cell 101 and 200 bead spacers (BS)per 1 mm² are provided in the general liquid crystal display panel. Inthis case, if it is assumed that the number of bead spacers (BS) perunit volume (1 mm³) is 1 in the liquid crystal lens cell 101, the numberthereof is 150 in the general liquid crystal display panel.

Accordingly, the surface area of the bead spacers (BS) relative to theliquid crystal unit volume is 2827=2827 μm²×1 in the liquid crystal lenscell and 7540=50 μm²×150 in the general liquid crystal display panel.

Thus, the surface area of the bead spacers (BS) in the liquid crystallens cell 101 is 37% of that in the general liquid crystal displaypanel.

The measurement of the water-absorbing ratio in the general liquidcrystal display panel with 150 bead spacers (BS) each having a size of 4μm per unit volume shows that water is absorbed at about 0.1 ppm/hr perunit volume.

On the other hand, the water-absorbing ratio of the liquid crystal lenscell 101 with 1 bead spacer (BS) having a size of 30 μm per unit volumeis about 37% of 0.1 ppm/hr, namely, 0.037 ppm/hr.

If it is assumed that the amount of moisture entering the inside of theliquid crystal lens cell 101 with 1 bead spacer (BS) having a size of 30μm per unit volume is 0.06 ppm/hr, it can be found that water cannot besufficiently absorbed with the amount of beads of the liquid crystallens cell 101.

On the other hand, in the case of the general liquid crystal displaypanel, moisture entering the inside of the liquid crystal layer can becompletely absorbed by the bead spacers (BS).

It should be noted that as preconditions of the above-describedcalculation formulas, it is assumed that 10 bead spacers (BS) eachhaving a size of 30 μm are dispersed per 1 mm² in the liquid crystallens cell 101.

However, if the dispersed amount of bead spacers (BS) is increased, thebead spacers (BS) become visible. Thus, 1/mm² is desirable. Under thecondition, it can be found that more moisture entering the inside of theliquid crystal lens cell 101 cannot be absorbed.

In the case where moisture enters the inside of the liquid crystal layerin a high temperature and humidity environment and then the temperatureis returned to room temperature, the saturated amount of moisture thatcan be dissolved in the liquid crystal layer is decreased, and thuswater is eluted, resulting in recognition as defects.

FIG. 8 shows a graph of a relation between a water vapor pressure andthe amount of moisture entering the liquid crystal layer.

The amount of moisture entering the liquid crystal layer is 0.06 ppm/hrat a water vapor pressure of 281 hPa (for example, temperature: 70° C.,humidity: 90%). However, the amount of moisture is 0.04 at 59 hPa (forexample, temperature: 36° C., humidity: 100%). Namely, in the case wherethe liquid crystal lens cell 101 without the water-absorption film 10 isleft in an environment at a water vapor pressure of 60 hPa or higher andmoisture the mount of which exceeds the limit that can be absorbed bythe liquid crystal layer (LC) enters, the water is eluted.

In order to solve the problem, the water-absorption film 10 is arrangedat the position shown in FIG. 2 in the embodiment. As described above,the water-absorption film 10 is configured using a transparent organicinsulating film such as acrylic resin or epoxy resin, and is extremelyhigh in water-absorbing ratio as compared to the bead spacers (BS).

Therefore, even if moisture enters the inside of the liquid crystallayer (LC) in a high temperature and humidity environment, no water isaccumulated in the liquid crystal layer (LC) until the water-absorptionfilm 10 becomes a saturated state in the embodiment. Even if, forexample, a transparent organic insulating film is used for the absorbingmember and is left for 2000 hr or longer in the environment such as atemperature of 70° C. and a humidity of 90%, the amount of moisture doesnot exceed the saturation value of the water-absorption film 10. Thus,there is no possibility of exceeding the saturated amount of moisture ina general usage environment.

An experiment was conducted to measure water absorbing time for each ofthe liquid crystal lenses having different water-absorption layerthickness after the liquid crystal lenses had been left in a certainenvironment. The certain environment is that leaving the liquid crystallens cell in a high temperature (70° C.) and humidity environment (90%)for 500 hours. Water absorbing time is defined as a time which moisturebegins to be absorbed by the water-absorption layer after the moisturepenetrate into the liquid crystal lens cell.

The measurement result is shown in FIG. 9. In the graph of FIG. 9, thehorizontal axis represents a liquid crystal layerthickness/water-absorption film thickness, and the vertical axisrepresents a water-absorbing time. The larger the horizontal axis is,the thinner the water-absorption film 10 becomes. It should be notedthat the thickness of the liquid crystal layer is 30 μm.

The water-absorbing time is saturated with a liquid crystal layerthickness/water-absorption film thickness of 7.5 or smaller. Namely, thewater-absorbing time is not changed. Further, the water-absorbing timeis drastically increased with a liquid crystal layerthickness/water-absorption film thickness of 100 or larger.

Accordingly, an area (C) of FIG. 9 is not desirable because thewater-absorbing time is drastically increased, and the liquid crystallayer thickness/water-absorption film thickness is desirably 100 orsmaller.

Further, it is necessary to thicken the thickness of thewater-absorption film 10 in an area (A) of FIG. 9. In addition, there isa possibility that the transmissivity is decreased due to lightabsorption by the water-absorption film 10, and thus the cost ofmaterial is increased due to the unnecessary film thickness. Further,since the water-absorbing time is sufficiently saturated with a liquidcrystal layer thickness/water-absorption film thickness of 7.5 orsmaller, 7.5<liquid crystal layer thickness/water-absorption filmthickness <100 is desirable.

Second Embodiment

FIG. 10 is a cross-sectional view for showing a cross-sectionalstructure of a liquid crystal lens cell 101 of a stereoscopic displaydevice according to a second embodiment of the present invention.

The second embodiment is different from the first embodiment in that awater-absorption film 10 is arranged on a first electrode (EL1) that isa comb-like electrode, and an oriented film (AL1) is arranged on thewater-absorption film 10 as shown in FIG. 10.

In the embodiment, if the water-absorption film 10 has insulationproperties, it is possible to prevent short-circuit caused by a contactbetween the first electrode (EL1) and a second electrode (EL2). Further,the arrangement of the water-absorption film 10 on the first electrode(EL1) can improve a water-absorbing ratio.

Third Embodiment

FIG. 11 is a cross-sectional view for showing a cross-sectionalstructure of a liquid crystal lens cell of a stereoscopic display deviceaccording to a third embodiment of the present invention.

The third embodiment is different from the first embodiment in that awater-absorption film 10 is arranged on a second electrode (EL2) that isa plane-like electrode on the side of a second substrate (SUB2) as shownin FIG. 11.

Accordingly, a water-absorbing ratio can be increased in the embodiment,and unevenness of the water-absorption film 10 caused by a step of thefirst electrode (EL1) that is a problem in the second embodiment can beimproved.

It should be noted that in each embodiment, the water-absorption film 10may be provided on each of the first substrate (SUB1) and the secondsubstrate (SUB2). If a decrease in transmissivity caused by lightabsorption of the water-absorption film 10 is taken into account, thewater-absorption film 10 is preferably provided on one of the firstsubstrate (SUB1) and the second substrate (SUB2).

The invention achieved by the inventors has been concretely describedabove on the basis of the embodiments. However, it is obvious that thepresent invention is not limited to the embodiments, but can bevariously changed without departing from the gist of the presentinvention.

Further, the present invention is not limited to the embodiments, butincludes various modifications. For example, the embodiments have beendescribed in detail to explain the present invention for easyunderstanding, and are not necessarily limited to those having the allconstitutional elements as described above. Further, a part of theconfiguration in one embodiment can be replaced by one in anotherembodiment, and the configuration in one embodiment can be added to onein another embodiment. In addition, a part of the configuration in eachembodiment can be added to or replaced by another, or deleted.

What is claimed is:
 1. A liquid crystal lens cell comprising: a firstsubstrate; a second substrate; a liquid crystal layer sandwiched betweenthe first substrate and the second substrate; a first electrode arrangedon the first substrate on the side of the liquid crystal layer; and asecond electrode arranged on the second substrate on the side of theliquid crystal layer, wherein the liquid crystal lens cell has awater-absorption film arranged on at least one of the first substrateand the second substrate on the side of the liquid crystal layer,wherein 7.5<(d/Th)<100 is satisfied, where the thickness of the liquidcrystal layer is d and the thickness of the water-absorption film is Th,and wherein the water-absorption film is arranged between the firstsubstrate and the first electrode.
 2. The liquid crystal lens cellaccording to claim 1, wherein the water-absorption film is made ofacrylic resin or epoxy resin.
 3. The liquid crystal lens cell accordingto claim 1, wherein the first electrode is a comb-like electrode, thesecond electrode is a plane-like electrode, and 3.5<(Q/d)<7 issatisfied, where the thickness of the liquid crystal layer is d and thepitch of the comb-like electrode is Q.
 4. The liquid crystal lens cellaccording to claim 3, wherein 4.5<(Q/d)<5.5 is satisfied.
 5. The liquidcrystal lens cell according to claim 4, wherein (Q/d)=5 is satisfied. 6.The liquid crystal lens cell according to claim 1, wherein the firstelectrode is a comb-like electrode, the second electrode is a plane-likeelectrode, and 10<(Q/L) is satisfied, where the pitch of the comb-likeelectrode is Q and the width of the comb-like electrode is L.
 7. Theliquid crystal lens cell according to claim 6, wherein 15<(Q/L)<20 issatisfied.
 8. The liquid crystal lens cell according to claim 1, whereinbead spacers arranged inside the liquid crystal layer are provided, andthe number of bead spacers per 1 mm² of the liquid crystal layer is 10or less.
 9. A liquid crystal lens cell comprising: a first substrate; asecond substrate; a liquid crystal layer sandwiched between the firstsubstrate and the second substrate; a first electrode arranged on thefirst substrate on the side of the liquid crystal layer; and a secondelectrode arranged on the second substrate on the side of the liquidcrystal layer, wherein a water-absorption film is arranged between thesecond substrate and the second electrode, and wherein 7.5<(d/Th)<100 issatisfied, where the thickness of the liquid crystal layer is d and thethickness of the water-absorption film is Th.
 10. The liquid crystallens cell according to claim 9, wherein the water-absorption film isarranged on the second electrode on the side of the liquid crystallayer.
 11. The liquid crystal lens cell according to claim 9, wherein7.5<(d/Th)<100 is satisfied, where the thickness of the liquid crystallayer is d and the thickness of the water-absorption film is Th.
 12. Theliquid crystal lens cell according to claim 9, wherein the firstelectrode is a comb-like electrode, the second electrode is a plane-likeelectrode, and 3.5<(Q/d)<7 is satisfied, where the thickness of theliquid crystal layer is d and the pitch of the comb-like electrode is Q.13. The liquid crystal lens cell according to claim 12, wherein4.5<(Q/d)<5.5 is satisfied.
 14. The liquid crystal lens cell accordingto claim 9, wherein the first electrode is a comb-like electrode, thesecond electrode is a plane-like electrode, and 10<(Q/L) is satisfied,where the pitch of the comb-like electrode is Q and the width of thecomb-like electrode is L.
 15. The liquid crystal lens cell according toclaim 14, wherein 15<(Q/L)<20 is satisfied.
 16. The liquid crystal lenscell according to claim 9, wherein bead spacers arranged inside theliquid crystal layer are provided, and the number of bead spacers per 1mm² of the liquid crystal layer is 10 or less.
 17. A liquid crystal lenscell comprising: a first substrate; a second substrate; a liquid crystallayer sandwiched between the first substrate and the second substrate; afirst electrode arranged on the first substrate on the side of theliquid crystal layer; and a second electrode arranged on the secondsubstrate on the side of the liquid crystal layer, wherein a firstwater-absorption film is arranged between the first substrate and thefirst electrode, wherein a second water-absorption film is arrangedbetween the second substrate and the second electrode, and wherein7.5<(d/Th)<100 is satisfied, where the thickness of the liquid crystallayer is d and the thickness of each of the first water-absorption filmand the second water-absorption film is Th.
 18. The liquid crystal lenscell according to claim 17, wherein bead spacers arranged inside theliquid crystal layer are provided, and the number of bead spacers per 1mm² of the liquid crystal layer is 10 or less.